Yehia Presents driller

8/10/2019 Yehia Presents driller

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High pressures and temperatures impact mud properties in a dynamic

way, and can have effects on well control

Small margins between pore and fracture pressures will prevail in

sections of the well

The conditions are above the critical point for the gas/oil/condensate

influx; which means that the hydrocarbon influx is infinite soluble in the

base oil of the mud.

Hydrocarbon influx will totally mix with the base oil in oil based mud

(OBM), and infinite amounts of gas can dissolve in the mud

Drilling of inclined and horizontal wells will make the consequences of

barite sag serious

Significant quantities of gas can diffuse into a horizontal section of a well

if OBM is used even if the well is overbalanced.

The drilling of HPHT wells pose special challenges compared to

standard wells :


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The objectives and motivation to perform modeling work in theplanning phase of an HPHT well are multiple:

. Address the concern over the high number of well control incidents during

drilling HPHT wells

. Address the fact that a growing number of well control incidents in HPHT

wells take place during completion

. Identify any well control risk for the particular well

. Confirm that existing procedures are according to best practice.

. Develop revised procedures if current procedures are not optimal

. Improve crew training and make it more relevant

The Objectives of Modeling Work in planning an HPHT Well


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Introduction


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Electronic components such as integrated circuits are frequently the weakestlink in a logging tools operational performance at high temperature. Typically,most electronic systems in logging tools are built from commercially availablehigh-temperature US military specified components.Increasing tool rating these commercial electronic systems are rated to 350 Ffor continuous operation.

The temperature increase inside a logging tool depends on two factors:

Drilling Logging

1- The heat flow from the outside environment

2-The heat dissipated by the power consumption of the internal components.


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Therefore, the use of low-power components and efficient circuit design helps

reduce the internal temperature increase coming from the heat generatedinside the tool.

Conventional logging tools (rated to 350 Fand 20,000 psi 1140 MPa) areupgraded to high-temperature specifications by installing all sensitive electroniccomponents in a 20,000-psi pressure-rated Dewar flask housing (above). The

Dewar flasks protect the electronic circuits from excessive boreholetemperatures. However, weight becomes a concern in HPHT wells because theflasks add weight to long combinations of tools. In deep HPHT well Is theadded cable tension from the additional weight of the flasked tools reduces theamount of pull that can be made on the cable before the limits of the weak pointare reached.

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Yehia Presents driller